I. Technical Field
This invention pertains to the field of electromagnetically operated actuators, and particularly to rotary actuators which provide limited bidirectional rotation.
II. Related Art and Other Considerations
A rotary actuator typically comprises a rotor shaft to which an inertial load can be connected or coupled for actuating (e.g., rotating) the load. Often the rotor shaft is rotated by electromagnetic means, e.g., electrical induction of a magnetic field causes traction and/or repulsion of magnetic elements to create a torque on the rotor shaft.
Some types of rotary actuators are bidirectional, meaning that a change in direction of the magnetic fields can cause the rotor shaft to rotate clockwise for a period of time and then counterclockwise for another period of time.
For some types of rotary actuators it is preferably that the extent of rotational motion in one or more directions (e.g., either clockwise or counterclockwise) be limited. However, precision in the limitation of rotational motion can be problematic.